Method of making cores for projectiles



April 1944- R. J. SOUTHWELL ET AL 2,346,462

METHOD OF MAKING CORES FOR PROJECTILES Filed Oct. 23, 1940 2 Sheets-Sheet 1 WRNEY April 1944- 7R. J.- SOUTHWELL ET AL 2,346,462

METHOD OF MAKING CORES FOR PROJECTILES Filed Oct. 23, 1940 2 Sheets-Sheet 2 ATTORNEY Patented Apr. 11, 1944 METHOD OF MAKING CORES FOR PROJECTILES Raymond J. Southwell, Nichols, and Edward A. Conner, Stratford, Conn., assignors to American Chain & Cable Company, Inc., New York, N. Y., a corporation of New York I Application October 23, 1940, Serial No. 362,342

8 Claims.

This invention relates to cores for projectiles and improved methods of manufacturing the same.

Among the objects of this invention are improved methods of manufacturing projectile cores or the like from low cost stock material, for example, carbon manganese molybdenum steel which will have the same penetrating qualities as cores made in accordance with present day methods from more expensive material such as tungsten steel now used in manufacturing projectile cores.

Another object of this invention is to so work the material during the manufacturing of the projectile core as to increase its density and its resistance against spreading and breaking upon impact and in such manner that the effeet of such working will not be removed by subsequent heat treatment.

Another object of this invention is to employ a method whereby the density of the metal of the core will be increased throughout its diameter and length and'the surfaces of the penetrating point and the body of the core will be made much smoother than by present day methods.

Other objects of the invention will appear from the following description of the method made with reference to the accompanying drawings, in which- Fig. 1 represents a length of round bar of stock used;

Fig. Zshows a lengthof the bar after its diameter has been reduced by a swaging operation Fig. 3 shows one end of the bar machined to be out to provide a blank with a boat tail end and a blunt conical penetrating point;

Fig. 4 shows the projectile core after the penetrating point has been finished by swaging;

Fig. 5 shows a swaged bar in the process of being cut into lengths providing projectile core blanks;

Fig. 6 shows the ends of the blank machined to provide a boat tail and a blunt conical penetrating point;

Fig. 7 shows the projectile corea-fter the penetrating point has been finished by swaging;

Fig. 8 shows a length of the bar stock used;

Fig. 9 shows one end of the bar machined to provide a blunt penetrating point;

Fig. 10 shows an end section of the bar reduced in diameter by swaging to provide the body and the sharp penetrating point of the projectile core;

Fig. 11 shows the projectile coresevered from the bar; and t Fig. 12 shows the projectile core after its rear end has been provided with a boat tail.

This invention is applicable to the manufacture of projectile cores or the like from any suitablematerial but for the purpose of (115010:

sure the invention has been described with reference to the manufacture of projectile cores from steel of the following analysis:

This invention is also applicable to the manufacture of cores of different calibers but for the purposes of disclosure. a description of the manufacture of .30 caliber cores is thought suificients In Fig. l. at 10 is shown a length of bar stock of the material above specified which may have been produced in any suitable manner, that is.

by rolling or drawing if desired, and for the .30 caliber core a bar stock of .281" diameter is preferably used.

This bar stock is passed through a swaging machine such as a rotary .swaging machine which delivers radially directed impacts on the surface of the bar which increases the density and toughness of the barthroughout its diameter and this operation is carried to an extent to produce the reduced diameter bar ll shown in Fig. 2 which in the production of the caliber core assumed is of .246" diameter. This operation also produces a smooth outer surface on the bar and a bar of uniform diameter.

As disclosed in Fig. 3 the bar is then machined to provide a blunt penetrating point 12 of about %12 of an inch in length at the free end of the bar and a boat tail end i3 producing a projectile core blank M which may be separated from the bar by severing the Same at the point l5 and if desired the new free end of the bar may be provided during this machining Operation with a 1blunt penetrating point as indicated by dotted mes.

The blunt penetrating point end section of the blank is then placed in a rotary swaging machine and the point together with the adjacentend of the cylindrical body part is then swaged down into the shape indicated at 16 Fig. 4, and to a length of of an inch producing the projectile core I! shown in Fig. 4.

The projectile core I! is then heated to 1525 F., oil quenched, and allowed to cool without drawing. It has been found that this heat treatment does not remove the efiects of the swaging operation.

Tests conducted with homogeneous steel plate show that the average indent for .30 caliber cores of the analysis stated and processed only on the point is .454" and that the average indent made by the same caliber cores of the same material and produced in accordance with this method is .5068". Tests also show that cores made of tungsten steel on a screw machine show an indent average of .5058" which is slightly less than the indent produced by a core of carbon manganese molybdenum steel of the analysis given and made by this method. Tungsten steel cores are also improved by this method.

As disclosed in Figs. 5, 6 and '7 the rotary swaged stock or bar disclosed in Fig. 2 may be severed into lengths l8 Fig. to provide projectile core blanks. Each of the blanks may then be turned down and the stock machined to provide a boat tail end I3 and a blunt penetrating point 12 as shown in Fig. 6, after which the penetrating point may bepointed and finished in a rotary swaging machine as described in connection with Fig. 4 to produce the projectile shown in Fig. 7.

In accordance with the method disclosed in Figs. 8 to 12, a length of bar stock [0 of .281" diameter is machined as at I2a in Fig. 9 to facilitate inserting the end of this bar in a rotary swaging machine and producing the finished point of the projectile core in such rotary swagingmachine. The bar is then inserted in a rotary swaging machine provided with dies which operate to produce the finished penetrating point 16 Fig. 10, and the body of the projectile core as indicated at 20 and a tapered section 2| which in the operation of producing the second projectile core serves the purpose of the tapered end l2a shown in Fig. 9. The cylindrical section of the bar which has been reduced by the swaging operation is then severed from the bar at the point indicated in Fig. 11 to produce a projectile core 22 which if desired may be provided with a boat tail l3 as indicated in Fig. 12.

The projectile cores made in accordance with the methods disclosed in Figs. 5, 6 and '7 and in Figs. 8 to 12 are heat treated in the same manner as those made by the method disclosed in Figs. 1 to 4.

A projectile, projectile core, bullet or the like manufactured in accordance with the methods disclosed will not mushroom or break upon impact with an object such as steel armor plate and as a result will have greater penetrating properties than cores made by known methods. The .term projectile is used in the claims in a generic sense.

While the invention has been described with particularity, it is to be understood that it is not limited to the caliber core herein referred to or to the particular character of material specified for purposes of description and that the right is reserved to all such changes in the product and in the steps of the method and to all such equivalent steps as fall within the principles of this invention and the scope of the appended claims.

What is claimed is:

1. The method of making a projectile which consists in reducing the diameter of bar stock to the diameter of the projectile to be produced by radially directed impacts, and pointing one end of the bar stock by radially directed impacts.

2. The method of making a projectile which consists in reducing the diameter, of bar stock to the diameter of the projectile to be produced by radially directed impacts, providing one end of the bar stock with a boat tail and the other end with a blunt penetrating point and pointing said blunt penetrating point by radially directed impacts.

3. The method of making a projectile which consists in reducing the diameter of bar stock to the diameter of the projectile to be produced by radially directed impacts, providing one end I directed impacts, and hardening the body portion and the point of the projectile so produced by heat treatment. v

5. The, method of making projectiles which consists in reducing the diameter of bar stock to the diameter of the projectiles to be produced by radially directed impacts, cutting the bar into projectile blank lengths, providing one end of each blank with a boat tail and the other end with a blunt penetrating point and pointing said blunt penetrating points by radially directed impacts.

' 6. The method of making projectiles which consists in reducing the diameter of bar stock to the diameter of the projectiles to be produced by radially directed impacts, cutting the bar into projectile blank lengths, providing one end of each blank with a boat tail and the other 'end with a blunt penetrating point, and pointing said blunt penetrating points by radially directed impacts upon said blunt penetrating points and the adjacent body portions of the blanks.

'7. The method of making projectiles which consists in reducing the diameter of bar stock to the diameter of the projectiles to be produced'by radially directed impacts, cutting the bar into projectile blank lengths, providing one end' of each blank with a boat tail and the other end with a blunt penetrating point, pointing said bluntpenetrating points by radially directed impacts, and hardening the body portions andthe points of the projectiles so'produced by heat treatment 8. The method of manufacturing projectiles which consists in reducing the diameter of an end section of bar stock by radially directed forces to produce the body and penetrating point of a projectile and a tapered section between the reduced and unreduced sections of the bar and in severing said bar at the junction of said tapered and reduced sections.

RAYMOND J. soUTHvvELL. EDWARD A. CONNER'. 

